[screensaver] Screen blanks during video playback in Chrome and Firefox under Xwayland

[Jean-Baptiste Lallement]

gnome-shell / gdm / wayland

Test Case:
1. Launch netflix in chrome
2. Play a video
3. Wait until the display times out.

Expected result
The screen does not dim

Actual result
The display goes black.

ProblemType: Bug
DistroRelease: Ubuntu 17.10
Package: gnome-shell 3.24.2-0ubuntu6
ProcVersionSignature: Ubuntu 4.10.0-22.24-generic 4.10.15
Uname: Linux 4.10.0-22-generic x86_64
ApportVersion: 2.20.5-0ubuntu4
Architecture: amd64
CurrentDesktop: GNOME
Date: Mon Jun 12 09:21:46 2017
DisplayManager: gdm3
InstallationDate: Installed on 2013-09-03 (1377 days ago)
InstallationMedia: Ubuntu 13.10 "Saucy Salamander" - Alpha amd64 (20130902)
ProcEnviron:
 TERM=screen-256color
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=fr_FR.UTF-8
 SHELL=/bin/bash
SourcePackage: gnome-shell
UpgradeStatus: No upgrade log present (probably fresh install)

[Daniel van Vugt (vanvugt)]

gnome-shell only knows that Chrome/Chromeium is running. It does not know what the browser is doing.

So if you want to disable blanking specifically during video playback, that's a browser enhancement. You might need to log a bug directly with Chromium/Chrome upstream.

[Jean-Baptiste Lallement (jibel)]

The behaviour is different in unity7 and gnome-shell. In unity7 screen blanking is disabled during video playback. Tested on the same machine with same settings.

On unity7 I did the following test:
1. Set screen blanking to 2 min
2. Wait 2 min with nothing playing
  -> The display goes black after 2 min
3. Play a netflix video in Chrome
  -> The display does not go black after 2 min

[Daniel van Vugt (vanvugt)]

Oh... probably a duplicate of bug 1692762 :)

[Jean-Baptiste Lallement (jibel)]

I am not sure it is a duplicate because I am using GDM

[Daniel van Vugt (vanvugt)]

Sorry, that's the opposite of your problem :)

Back on topic with this bug...

I don't know what API(s) are being used by the browser to disable video playback, but there are only a few probable options:

  (a) The API is different between telling Unity7 and Gnome Shell to not blank, and Chrome doesn't support the latter; or
  (b) The API is different between telling Unity7 and Gnome Shell to not blank, and Chrome does support both but gnome-shell is ignoring it; or
  (c) The API is the same for both Unity7 and Gnome Shell, and gnome-shell is ignoring it.

So yeah, in both (b) and (c) we would need a gnome-shell task. But there are many possible reasons as to why this is broken. Needs more research.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Daniel van Vugt (vanvugt)]

It appears that Xwayland on artful has no DPMS support yet:

https://cgit.freedesktop.org/xorg/xserver/tree/Xext/dpmsstubs.c?h=server-1.19-branch
https://cgit.freedesktop.org/xorg/xserver/tree/hw/xwayland/Makefile.am?h=server-1.19-branch

So Chromium can't use DPMS to disable blanking:

https://chromium.googlesource.com/chromium/src.git/+/master/device/power_save_blocker/power_save_blocker_x11.cc#427

Looks like the situation is changing in trunk Xorg/Xwayland but unclear what the status of DPMS support is (dpmsstubs.c no longer exists).

[Daniel van Vugt (vanvugt)]

Assigned to xorg-server because the feature simply does not exist in Xorg/Xwayland 1.19.

Either Xwayland (source: xorg-server) needs enhancement to support DPMS, or Chromium needs enhancement to use something other than DPMS.

[Olivier Tilloy (osomon)]

chromium 61.0.3163.31 (from the beta channel) still affected.

[Chai T. Rex (chaitrex)]

Relevant Chromium bug is #783737: https://bugs.chromium.org/p/chromium/issues/detail?id=783737

[funicorn (funicorn)]

I confirm that also happens in firefox 57 on Ubuntu 17.10.

Firefox: 57.0
Ubuntu: 17.10
Gnome-shell 3.26.2
xwayland:2:1.19.5-0ubuntu2

PS I noticed there is a '-v' option for wayland that runs with "screen-saver without video blanking". Is that helpful?

[Daniel van Vugt (vanvugt)]

From what I can tell, Xwayland is still missing DPMS support:
https://cgit.freedesktop.org/xorg/xserver/tree/hw/xwayland/

And that's still what all X apps need to use. For example:
https://chromium.googlesource.com/chromium/src.git/+/master/services/device/wake_lock/power_save_blocker/power_save_blocker_x11.cc

This is a bug in Xwayland only. Xwayland needs to be modified to convert DPMS requests from clients like web browsers into calls to this:
https://cgit.freedesktop.org/wayland/wayland-protocols/tree/unstable/idle-inhibit

[Or Schiro (orschiro)]

As a workaround I found this GNOME extension:

https://extensions.gnome.org/extension/517/caffeine/

If you go into F11 fullscreen during playback, the screen no longer blanks. :-)

[Nicolás Abel Carbone (nicocarbone)]

Still happpening in Ubuntu 18.04. Maybe not that important now that wayland is not the de default session, but nonetheless worth of fixing I think

[satya gowtham (satyagowtham-k-gmail)]

its problem with vlc as well; I'm neither using wayland.

[Mike (0x656b694d)]

Still there with Ubuntu 19.10.

[Krishnakanth (krish9861)]

yah it affects my new installation of ubuntu 18.04 lts

[john (yegnal)]

Yes, cannot watch video without display locking

[Abdulla Masud (abdulla95)]

Having this issue on Xubuntu 19.10

[Jason Mitchell (jasonjamesmitchell)]

Having this issue on Lubuntu 20.04.1 as well.

[Hicks (hicks1gb)]

Ubuntu hirsute hippo too

[Roberto López López (bergensk)]

same here with xubuntu 22.04.1 - does anyone else care about this problem? I would not mind to fix it by myself, but my C knowledge is pretty basic